Change github action to use python 3.8

Author: whoseoyster

.github/workflows/publish.yml

@@ -15,9 +15,10 @@ jobs:
       - name: Set up Python 3.9
         uses: actions/setup-python@v1
         with:
-          python-version: 3.9
+          python-version: 3.8
       - name: Install openlayer
         run: >-
+          python -m pip install --upgrade pip
           pip install -e .
       - name: Install pypa/build
         run: >-